Strawberry species of Iturup and Sakhalin Islands

Abstract

A plant-collecting expedition to Iturup and Sakhalin Islands, Sakhalin Territory, Russian Federation, occurred between 21 July and 12 Sept. 2003. Strawberries, Fragaria L., were observed and collected. Japanese and Russian flora describe two diploid (2n = 2x = 14) species, F. iinumae Makino and the Yezoensis strawberry, F. nipponica Makino [syn. = Fragaria nipponica var. yezoensis (H. Hara) Kitam.], as native to those islands. In addition, a recent monograph described a new octoploid (2n = 8x = 56) strawberry species, F. iturupensis Staudt, from a Japanese herbarium specimen collected on Atsunupuri volcano near Lesozovodoskyi, Iturup, in 1929. The objectives of the 2003 collecting trip were to obtain wild strawberries from these islands and determine if a population of F. iturupensis still existed on the volcano. The native F. iinumae Makino was obtained from the Ogonki Village, Anivskyi Region, Southern Sakhalin Island, but was not observed on Iturup. The Yezoensis strawberry was observed at Cape Otlivnoy, Iturup. Two small colonies of the native octoploid F. iturupensis Staudt were collected from mid-elevations on the east-facing slope of Atsunupuri volcano. The native distribution of F. iturupensis was limited to this volcanic montane habitat and was not found in the foggy, sandy locations of coastal elevations on Iturup. The leaf morphology and growth habit of F. iturupensis plants were similar to that of F. virginiana subsp. glauca (S. Watson) Staudt of North America, but the fruit was different, more like F. vesca L. Probable cultivated escapes were observed at two sites on the east coast of Iturup and at one site in southern Sakhalin. The 2003 expedition confirmed the existence of F. iturupensis, the only known native Asian octoploid strawberry on Atsunupuri. Limited quantities of germplasm are available for research from the curator, U.S. Department of Agriculture, Agricultural Research Service, National Clonal Germplasm Repository, Corvallis, OR, the U.S. national strawberry gene bank.